Table 2.
Comparison of survival, fertilization, pregnancy, and implantation rates of vitrified human oocytes
| groups | group 37 °C | group RT | P value | |||
|---|---|---|---|---|---|---|
| Nondonor oocytes | Donors oocytes | Nondonor oocytes | Donor oocytes | Nondonor oocytes | Donor oocytes | |
| No. of cycles | 70 | 71 | – | |||
| 35 | 35 | 37 | 34 | – | – | |
| No. of vitrified–thawed oocytes | 662 | 676 | – | |||
| 330 | 332 | 349 | 327 | – | – | |
| Survival (%) | 585(88.37) | 540(79.88) | 0.0000 | |||
| 288(87.27) | 297(89.42) | 264(75.64) | 276(84.40) | 0.0001 | 0.0541 | |
| No. of fertilized (2PN) zygotes (%) | 390(66.67) | 353(65.37) | 0.6464 | |||
| 194(67.36) | 196(65.99) | 181(68.56) | 172(62.32) | 0.7629 | 0.3592 | |
| No. of ET/FET cycles | 64 | 60 | – | |||
| 28 | 36 | 31 | 29 | – | – | |
| No. of clinical pregnancies (%) | 24(37.5) | 21(35.0) | 0.7723 | |||
| 8(28.57) | 16(44.44) | 8(25.81) | 13(44.83) | 0.8115 | 0.9754 | |
| No. of implantations (%) | 33(20) | 29(19.46) | 0.9050 | |||
| 11(14.86) | 22(24.18) | 10(13.33) | 19(25.68) | 0.7882 | 0.8245 | |
| Miscarriage (%) | 5(16.67) a | 4(19.05) | 0.6970 | |||
| No. of deliveries | 19 | 17 | – | |||
| No. of live births | 23 | 23 | – | |||
| 7 | 16 | 9 | 14 | – | – | |
| Percentage of oocytes to achieve a live birth % | 3.47 | 3.40 | 0.9444 | |||
| 2.12 | 4.82 | 2.58 | 4.28 | 0.7012 | 0.7516 | |
| Singleton/Multiple pregnancies | 15/4 | 12/5 | – | |||
| No. of deliveries at <37 weeks (%) | 5(26.32) | 4(23.53) | 0.7166 | |||
| No. of low birth weight (%) | 6(26.09) | 3(13.04) | 0.2295 | |||
| Congenital anomalies | 0 | 0 | – | |||
a: including one abortion of twin pregnancy at 24 weeks
Fertilization rate = No. of 2PN zygotes/ No. of survival oocytes
Implantation rate = No. of gestational sacs/No. of embyos transferred
Clinical pregnancy rate = No. of patients with ultrasound evidence of a gestational sac/No. of embyos transferred cycles